wxWidgets offers an alternative drawing API based on the modern drawing
backends GDI+, CoreGraphics and Cairo. See wxGraphicsContext, wxGraphicsRenderer
and related classes. There is also a wxGCDC linking the APIs by offering
- the wxDC API ontop of a wxGraphicsContext.
+ the wxDC API on top of a wxGraphicsContext.
wxDC is an abstract base class and cannot be created directly.
Use wxPaintDC, wxClientDC, wxWindowDC, wxScreenDC, wxMemoryDC or
@section dc_alpha_support Support for Transparency / Alpha Channel
- On Mac OS X colours with alpha channel are supported. Instances of wxPen
- or wxBrush that are built from wxColour use the colour's alpha values
- when stroking or filling.
+ In general wxDC methods don't support alpha transparency and the alpha
+ component of wxColour is simply ignored and you need to use wxGraphicsContext
+ for full transparency support. There are, however, a few exceptions: first,
+ under Mac OS X colours with alpha channel are supported in all the normal
+ wxDC-derived classes as they use wxGraphicsContext internally. Second,
+ under all platforms wxSVGFileDC also fully supports alpha channel. In both
+ of these cases the instances of wxPen or wxBrush that are built from
+ wxColour use the colour's alpha values when stroking or filling.
+
+
+ @section Support for Transformation Matrix
+
+ On some platforms (currently only under MSW and only on Windows NT, i.e.
+ not Windows 9x/ME, systems) wxDC has support for applying an arbitrary
+ affine transformation matrix to its coordinate system. Call
+ CanUseTransformMatrix() to check if this support is available and then call
+ SetTransformMatrix() if it is. If the transformation matrix is not
+ supported, SetTransformMatrix() always simply returns false and doesn't do
+ anything.
@library{wxcore}
character with the given index if it is != -1 and return the bounding
rectangle if required.
*/
- void DrawLabel(const wxString& text, const wxBitmap& image,
+ void DrawLabel(const wxString& text, const wxBitmap& bitmap,
const wxRect& rect,
int alignment = wxALIGN_LEFT | wxALIGN_TOP,
int indexAccel = -1, wxRect* rectBounding = NULL);
/**
@overload
*/
- void DrawRotatedText(const wxString& text, const wxPoint&,
+ void DrawRotatedText(const wxString& text, const wxPoint& point,
double angle);
/**
@note The present implementation for non-Windows platforms may fail to
find colour borders if the pixels do not match the colour
exactly. However the function will still return @true.
+
+ @note This method shouldn't be used with wxPaintDC under non-Windows
+ platforms as it uses GetPixel() internally and this may give
+ wrong results, notably in wxGTK. If you need to flood fill
+ wxPaintDC, create a temporary wxMemoryDC, flood fill it and then
+ blit it to, or draw as a bitmap on, wxPaintDC. See the example of
+ doing this in the drawing sample and wxBufferedPaintDC class.
*/
bool FloodFill(wxCoord x, wxCoord y, const wxColour& colour,
wxFloodFillStyle style = wxFLOOD_SURFACE);
@overload
*/
bool FloodFill(const wxPoint& pt, const wxColour& col,
- int style = wxFLOOD_SURFACE);
+ wxFloodFillStyle style = wxFLOOD_SURFACE);
/**
Displays a cross hair using the current pen. This is a vertical and
@note Setting a pixel can be done using DrawPoint().
+ @note This method shouldn't be used with wxPaintDC as accessing the DC
+ while drawing can result in unexpected results, notably in wxGTK.
+
@beginWxPythonOnly
The wxColour value is returned and is not required as a parameter.
@endWxPythonOnly
'zooming'.
*/
void SetUserScale(double xScale, double yScale);
+
+
+ /**
+ @name Transformation matrix
+
+ See the notes about the availability of these functions in the class
+ documentation.
+ */
+ //@{
+
+ /**
+ Check if the use of transformation matrix is supported by the current
+ system.
+
+ Currently this function always returns @false for non-MSW platforms and
+ may return @false for old (Windows 9x/ME) Windows systems. Normally
+ support for the transformation matrix is always available in any
+ relatively recent Windows versions.
+
+ @since 2.9.2
+ */
+ bool CanUseTransformMatrix() const;
+
+ /**
+ Set the transformation matrix.
+
+ If transformation matrix is supported on the current system, the
+ specified @a matrix will be used to transform between wxDC and physical
+ coordinates. Otherwise the function returns @false and doesn't change
+ the coordinate mapping.
+
+ @since 2.9.2
+ */
+ bool SetTransformMatrix(const wxAffineMatrix2D& matrix);
+
+ /**
+ Return the transformation matrix used by this device context.
+
+ By default the transformation matrix is the identity matrix.
+
+ @since 2.9.2
+ */
+ wxAffineMatrix2D GetTransformMatrix() const;
+
+ /**
+ Revert the transformation matrix to identity matrix.
+
+ @since 2.9.2
+ */
+ void ResetTransformMatrix();
+
+ //@}
+
+
+ void SetLogicalScale(double x, double y);
+ void GetLogicalScale(double *x, double *y) const;
+ void SetLogicalOrigin(wxCoord x, wxCoord y);
+ void GetLogicalOrigin(wxCoord *x, wxCoord *y) const;
+ wxPoint GetLogicalOrigin() const;
+
};
The clipping region is automatically unset when this object is destroyed.
*/
- wxDCClipper(wxDC& dc, const wxRegion& r);
+ wxDCClipper(wxDC& dc, const wxRegion& region);
wxDCClipper(wxDC& dc, const wxRect& rect);
wxDCClipper(wxDC& dc, wxCoord x, wxCoord y, wxCoord w, wxCoord h);
//@}
projects / wxWidgets.git / blobdiff